Abstract
Detrital mica ages in the Southern Uplands range from 458 to 502 Ma. The evidence favours a source in a basement which was part of an arc complex to the north rather than from the Dalradian block which also has mica ages of this range. No Grenville ages have yet been recorded. Detrital volcanic clasts dispersed from the south have cooling ages of 560 and 530 Ma indicating that they did not come from a contemporary arc, but an older arc terrane of uncertain affinities.